102640 has 20 divisors (see below), whose sum is σ = 238824. Its totient is φ = 41024.

The previous prime is 102611. The next prime is 102643. The reversal of 102640 is 46201.

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 102640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 562 + ... + 721.

2¹⁰²⁶⁴⁰ is an apocalyptic number.

102640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

102640 is an abundant number, since it is smaller than the sum of its proper divisors (136184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

102640 is a wasteful number, since it uses less digits than its factorization.

102640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1296 (or 1290 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 102640 is about 320.3747805306. The cubic root of 102640 is about 46.8208055154.

Adding to 102640 its reverse (46201), we get a palindrome (148841).

The spelling of 102640 in words is "one hundred two thousand, six hundred forty".